Bump storybook-dark-mode from 1.1.2 to 3.0.3 in /legacy

Bumps [storybook-dark-mode](https://github.com/hipstersmoothie/storybook-dark-mode) from 1.1.2 to 3.0.3.
- [Release notes](https://github.com/hipstersmoothie/storybook-dark-mode/releases)
- [Changelog](https://github.com/hipstersmoothie/storybook-dark-mode/blob/master/CHANGELOG.md)
- [Commits](hipstersmoothie/storybook-dark-mode@v1.1.2...v3.0.3)

---
updated-dependencies:
- dependency-name: storybook-dark-mode
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

legacy/package.json

@@ -87,6 +87,6 @@
     "bigtest": "^0.14.0",
     "netlify-cli": "^12.2.8",
     "storybook-addon-gatsby": "^0.0.5",
-    "storybook-dark-mode": "^1.0.8"
+    "storybook-dark-mode": "^3.0.3"
   }
 }